The alien epoxy comes in tubes and, when used, restores the condition of the player's currently-equipped weapon. The weapon must be equipped in order for the epoxy to repair it, therefore alien epoxy cannot repair broken weapons. While the effect of one tube may not completely repair a weapon, applying multiple tubes one after the other (regardless of Repair skill) can increase a weapon's condition to 100%.
Since normal "Earth-made" weapons are rare aboard the ship, alien epoxy is an excellent alternative to using salvaged weapons for repair. It also has no weight allowing them to be carried en masse.
Effects of Repair skill[]
Repair skill
0 - 24
25 - 49
50 - 74
75 - 100
Condition
+15%
+20%
+25%
+30%
Locations[]
Alien epoxies can usually be found on alien workers.
They can additionally be found in containers throughout the mothership.
Alien epoxy can be found in the "Aid" section of the Pip-Boy.
Behind the scenes[]
An "epoxy" is a step-growth thermoset polymer that solidifies around the applied area. This fits, suggesting that the epoxy fills in cracks or faults in the weapon.